* {
	padding: 0px;
	margin: 0px;
}
html,
body,
#app {
	width: 640px;
	height: 100%;
}
.main {
	min-width: 320px;
	max-width: 640px;
	width: 640px;
	margin: 0 auto;
}
.fl {
	float: left;
}
.fr {
	float: right;
}
.clearfix::after {
	content: '';
	clear: both;
	display: block;
}

ul,
ol {
	list-style: none;
}
